Copyright Goodheart-Willcox Co., Inc.
214
Two-Stroke Engines
Copyright Goodheart-Willcox Co., Inc.
Summary
• A visual inspection is the first step of troubleshooting or evaluating a
two-stroke engine.
• After the visual inspection, the troubleshooting process is an attempt to
identify an engine problem and make an immediate repair.
• The goal of troubleshooting is to get the unit back out in the field as
soon as possible.
• Evaluating the engine involves a very thorough inspection of any and
all faults that would cause the engine to run poorly or not all.
• When the engine is repaired, it should run and operate correctly.
• The engine and its operational load should be tested before returning it
to the customer.
• When the equipment is returned to the field, it should operate well
within the emission standards set by the EPA.
Review Questions
1. In one position, a stop switch shows continuity. In the other position,
there is no continuity. Is the switch working correctly?
2. The engine does not have spark. In the “OFF” position, the stop switch
has continuity. Is the switch bad?
3. Ethanol is hygroscopic. That means _____.
A. ethanol absorbs moisture
B. ethanol is grown in water and no dirt
C. ethanol provides lubrication
D. ethanol absorbs minerals from the gasoline
4. The AV system is the _____.
A. audio visual system that reduces two-stroke engine noise
B. anti-volatility system that reduces two-stroke engine emissions
C. anti-vibration system that reduces two-stroke engine vibrations
D. additional-vibration system that counteracts engine vibrations
5. When the engine is running at 14,520 rpm, how many revolutions does
the crankshaft make in one second?
A. 29,040
B. 7,260
C. 2,416
D. 242
6. True or False? When testing the output from the purge prime system,
pressing and releasing the bulb should cause a pressure gauge needle
to rise.
7. A smooth, dull piston skirt with no scratches indicates _____.
A. the piston is still okay
B. the piston has some abrasive wear
C. the piston is okay, but needs lubricating oil
D. the piston is worn, but acceptable to use